Dobby machine

ABSTRACT

A dobby machine has retaining hooks which are guided for rectilinear reciprocal movement and are connected by pivoted links to opposite ends of a rocking member connected by linkage with a heald or dobby shaft. Each of two two-part levers comprises two lever parts which are pivoted about a common pivot and are movable relative to one another. One lever part has a hook portion and constitutes a holding hook engageable with the respective retaining hook. The other lever part carries a reading needle for sensing a pattern controlling the machine and has a portion engageable with the holding hook lever part to control whether or not the holding hook is in position to engage the respective retaining hook. When the hooks are engaged with one another, a locking member releasably engages the holding hook to hold it in engaged position. However, the holding hook is movable longitudinally relative to its pivot to free it from the locking member.

United States Patent [72] inventors .Imeph Pahu 3,381,719 /1968 Favre139/68 Frlnkreich,Frlnoe; 3,441,060 4/1969- Schwarz 139/68 RudollSchwan,Bergen-Zurich, 3,459,236 8/1969 Favre 139/71 SWIM FOREIGN PATENTS Q55"-23 :2 473,919 7/1969 Switzerland 139/71 9 [45] Patented Aug. 31, 1971Primary Examiner-James Kee Chi [73] Assignee Staubll Ltd.Attorneys-Robert E. Burns and Emmanuel J. Lobato Horgen-Zurich,Switzerland 32 Priori A r.2 1968 Mar.2l 1969 l ty p ABSTRACT: A dobbymachine has retainin hooks which are [33] Switzerland 8 [31] 4863/68 and4268/69 guided for rectilinear reciprocal movement and are connected 8by pivoted links to opposite ends of a rocking member connected bylinkage with a heald or dobby shaft. Each of two two-part leverscomprises two lever parts which are pivoted [54] DOBBY MACHINE m 10nnwingmgs. about a common pivot and are movable relative to one another.One lever part has a hook portion and constitutes a [52] US. Cl 139/71holding hook engageable with the respective retaining hook [511 CL D036U06 The other lever part carries a reading needle for sensing a pat-[50] Field ofscll'dl l39/7l,68, em commmng the machine and h a portionengageable 71 Av 66 with the holding hook lever part to control whetheror not the holding hook is in position to engage the respectiveretaining I56] Rem mm Cited hook. When the hooks are engaged with oneanother, a UNITED STATES PATENTS locking member releasably engages theholding hook to hold it 2,976,891 3/1961 Wicker 139/71 in engagedposition. However, the holding hook is movable 3,285,291 11/1966 Favre139/68 longitudinally relative to its pivot to free it from the locking3,307,591 3/1967 Staubli 139/71 member.

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sum 6 [IF 6 DOBBY MACHINE ln known dobby machines for controlling themovement of Y loom shafts, reading of a perforated pattern card takesplace in a time interval during which a shaft is being raised orlowered, and a preliminary needle system is normally required. An objectof this invention is the provision of a direct-acting reading system,which may be applied to a known kind of dobby machine mechanism and inwhich the ends .of a rocker element are alternately struck by crosspieces; retaining hooks are secured in position according to aparticular pattern being used and a shift in the reading action takesplace in a time interval during'which the loom shed is stationary.

The invention provides a dobby machine in which the position of at leastone retaining hook, which is connected to an associated shaft or to aheald by way of a mechanical linkage, is adapted to be controlled by aperforated card, by means of a two-part lever whose two constituentparts are mounted on a common pin and are angularly moveable relative toone another; under the action of a spring, each of the lever partsabutting a stop element on the other lever part; and machine beingcharacterized in that a first part of the lever carries a reading needlewhich, together with the first lever part, is adapted to be periodicallylifted by a drive member from the pattern card against the biasing forceof a spring, and the first lever part is adapted to be released so thatit can move towards the pattern card; and the other part of the lever,is adapted to control the position of the retaining hook either byreleasing the hook or, by engaging under or in the hook.

Theoretical and practical tests on the above-described dobby machinehave shown that there is obtained-by reason of a reading clearancebetween retaining hook and holding hookwhich is necessary forsatisfactory functioninga stationary condition of the shed over anangular range of 5862 in respect of the drive crankshaft. In the case ofa reading clearance of 3-5 mms. this corresponds to an angular range ofabout 19-3 lon the camshaft of the dobby machine.

An embodiment of the invention is illustrated by way of an example inthe accompanying drawings, in which:

H6. 1 is a diagram representing the movements of the driven parts of adobby machine;

FIG. 24 each show, diagrammatically, a different position of the dobbymachine;

FIGS. 5 and 6 show details relating to the movement of reading needles,in two respective positions of the needles and on an enlarged scale; and

FIGS. 7-10 are each plan views of a section of a pattern card withreading needles in position.

Before any movement of the dobby mechanism is described, and beforereference is made to the associated diagram, the principle features ofthe structure of the dobby machine will be explained with reference toFIG. 2.

Lower and upper thruster crosspieces 11 and 21 respectively adapteduniformly to swing to and fro about a pin 1, lie against the respectiveends 12, 22 of a rocker member 2. Articulated to the center of therocker member 2 is a pivot lever 3 which is supported from a shaft 4 andis connected, by way of pull rod 5, to a dobby shaft, not shown.Retaining hooks 14, 24 are respectively articulated, by way ofconnecting bars 13, 23 to the respective ends 12, 22 of the rockermember. Under the effect of impact by the thruster crosspieces ll, 21,the retaining hooks 14, 24 slide in respective guides 15, 25 whichensure that they are accurately guided.

A perforated pattern card 6 serves to control the movement and inparticular the position of the dobby shaft, this pattern card 6 beingdriven-by card cylinder 7, with reading needles 30, 40 reading the holesconstituting the pattern. Two-part levers 32, 42 are mounted onrespective pins 31, 41; the first lever parts 33, 43 carrying therespective reading needles 30, 40, and the second lever parts 34a, 44abeing formed as holding hooks 35a, 45a.

- lie against one another in the region of stops 36, 46 under thebiasing force of tension springs 37a, 47a and of compression springs39,49. The second lever parts 34a, 44a are not only rotatably mountedbut also slidably mounted, by way of slots 50, 60, on pins 31, 41. Toraise levers 32, 42, that is to say to lift the reading needles from outof the pattern card, use is made of rotating cams 38, 48, while thecompression springs 39, 49 press the first lever parts 33, 43respectively against their associated cams.

Slidable locking members 17, 27, which are actuated by the machine drive(not shown), are capable of executing reciprocating movement. The pointsor tips of the holding hooks 35a, 45a, which face towards the slidablelocking members 17, 27, each comprise a notch 51, 61 whose shape iscomplementary to that of the wedge-shaped tip of the slidable lockingmembers 17, 27.

In a known manner FIG. 1 relates the points of time at which themovements of the various driven members of the dobby machine occur inrelation to the angular movements of the camshaft. Thus:

A is a curve representing the movement of the lower thruster cross piece11, B is a curve representing the movement of the upper thruster crosspiece 21,

C is a curve representing the movement of the control cylinder 7 of thepattern card 6,

D is a curve representing the movement of the earns 38, 48 for liftingthe needles from the pattern card,

E is a curve representing the movement of the lower slidable lockingmember,

F is a curve representing the movement of the upper slidable lockingmember,

G is a curve representing the movement of the needle guide 62 for theeven-numbered picks (weft),

H is a curve illustrating the movement of the needle guide 52 for theodd-numbered picks (weft).

The diagram, taken in conjunction with FIGS. 3 and 4, illustrates thepoints of time at which the positions illustrated in the FIGS. areassumed. FIGS. 2 and 4 illustrate the lower shed position of the dobbyshaft, and FIG. 3 the upper shed position thereof.

The manner of operation of the dobby machine will now be furtherelucidated with reference to the different FlGS. In F I68. 3 and 4 onlythose parts are referenced which are necessary for illustrating thefunctioning of the machine, the reference numerals corresponding tothose of FIG. 2.

In the position illustrated in FIG. 2 the upper cross piece 21 is shownmoving to the rear after it has struck against the retaining hook 24.The needle 40 lies against the pattern card 6, as no hole is present forreading at that point. The holding hook 45a is raised and is secured inposition by the slidable locking member 27, so that the retaining hook24 follows the crosspiece 21 to the right, this movement being initiatedby the tensioning force of the pull rod 5. The lower retaining hook 14is also in the inward position and the holding hook 35a is held inposition by the slidable locking member 17. The dobby shaft is in thelower shed position.

In the position illustrated in FIG. 3 the upper retaining hook 24 is-asdetermined by the configuration of the pattern card-held in itsoutwardly thrust position by the holding hook 45a, in which the tip ofthe slidable locking member 27 firmly engages in the notch. Subject tothe biasing force of spring 49, the reading or sensing needle 40 oflever 42 has penetrated a hole in the pattern card 6, and the holdinghook 45a is secured in position by slidable locking member 27. Thisposition of the upper hooks 24, 45a remains unaltered until the next butone reading action performed by the needles. The lower thruster crosspiece 11 is about to assume its most forwardly advanced position, thatis to say the lower retaining hook 14 is also in its outwardly thrustposition. As the upper hooks- 24, 45a are in interlocking connectionwith one another, the dobby shaft is about to assume the upper shedposition. Movement of lower holding hook 350 is still prevented owing tothe presence of slidable locking member 17 which engages the notch 51 inits tip. At the next instant of time the slidable locking member 17 willbe withdrawn so that the holding hook 35a will be freed for thefollowing control action, as determined by the pattern on the patterncard. The cams 38, 48 then come into operation, that is to say bothfirst parts 33, 43 of the two-part levers 32, 42 are pivoted, byrotation of the cams, into the position shown in FIG. 4, so that thereading needles 30, 40 are lifted from the pattern card.

FIG. 4 shows the dobby mechanism at another instant of the working cycleand reads a difierent pattern on the pattern card from that which wasread in the case of FIGS. 2 and 3. As determined by the pattern card thelower holding hook 35a does not interlockingly engage with retainingbook 14. It is however secured by the slidable locking member 17 in-thenonengaging position. The upper crosspiece 21 has struck against theupper retaining hook and the slidable locking member retracted, so thatthe two hooks 45a, 24 are ready to enter into locking engagement as soonas the reading needle 40 lies in front of a hole in the pattern card 6.The reading needles 30 and 40 are lifted, as the cams 38, 48 havepivoted their carrier levers 33, 43 about the pins 31 and 41respectively. The pattern card can be moved forward by the cylinder 7 tothe extent of one further pick. At the same time the needles 30, 40 arecaused, by the needle guides 52, 62, to execute a further movement whichwill be described below.

The pivotal movements, initiated by the cams 38, 48, of the parts 33, 43may take place independently of the position of the holder hooks 35a,45a and irrespective of the fact that these hooks 35a, 45a are retainedin position by the slidable locking members 17, 27, because the levers32, 42 are constructed as double levers which can execute pivotalmovements relative to one another. If part 33 in FIG. 4 is relieved bythe further rotation of cam 38, then lever 32 will remain in itsoriginal position, as it is maintained in position by the slidablelocking member 17. In the course of further rotation of cam 48, however,spring 49 pivots lever 42 against the biasing force of spring 470, sothat the reading needle 40 lies against the pattern card 6. If a hole ispresent in the pattern card 6, then lever 42 assumes the position shownin FIG. 3; if no hole is present in the pattern card in front of theneedle, then the lever 42 assumes the position shown in FIG. 2.

After interlocking engagement has taken place between holding hook 45aand retaining hook 24 the position illustrated in FIG. 3), the tip ofthe slidable locking member 27 engages, in the course of its forwardmovement, into the notch 61 and at the same time shifting part 44a tothe left, so that the reading clearance between the two hooks 45a and 24is eliminated. The mounting of part 44a in the elongate hole 60 enablesthis movement to take place against the tensioning effect of spring 470.The thruster cross piece 21 only commences its rearward pivotal motionwhen the holding hook 45a is held in position by the slidable lockingmember 27. Thus, the mechanism illustrated enables elimination of theknown reading play between the contact surfaces of the holding hooks andthe retaining hooks, this play being necessary for correct functioning;consequently, the dobby shaft can operate substantially without jolts orshocks.

The sequence of actions described below applies both to the upper andlower mechanisms, although they are only described in relation to theupper mechanism. TI-Ie elongate hole in part 440 is made sufficientlylong to ensure that it serves as a securing means when the machine isnot operated in the correct sequence, for example when the pattern cardis being changed or when the machine is incorrectly handled. If

the retaining hook 24 should in this way be unexpectedly thrust forwardby its thruster cross pieces 21-the corresponding holding hook 440 beingheld in the position of interlocking engagement (FIG. 3)-then this wouldlead 3)-damage being inflicted on the machine. In the present instance,however, the head of the retaining hook 24 presses against the holdinghook 45a and shifts it further to the left-this being permitted by theelongate hole 60-until it is pulled round the tip of the slidablelocking member 27 by the spring 47 a.

With the above described arrangement, the slidable locking member27-when the holding hooks and retaining hooks are in mutual retainingengagement-assumes the function of holding the dobby shaft in the raisedposition. It is now the slidable locking member 27, and no longer themounting pin 41, which bears the weight of the dobby shaft. It is thuspossible, firstly, to make the part 44a and the bearing 41 lighter thanin conventional machines and, secondly, to reduce the friction at thebearing 41. The result of this is that friction and inertia no longerreduce the reading speed to the same extent as with conventionalmachines so that an increase in the operating speed is possible. At thesame time this arrangement enables lighter compression springs 49 to beused, which causes the reading needle 40 to bear with less weight on thepattern card and thus cause less wear thereto.

To enable the above described dobby machine with two reading needles perdobby shaft to function automatically, that is to say in the correctworking sequence, in both forward and backward motion, the readingneedles 30, 40 are connected to the double levers 32, 42 in anarticulated manner and are guided in guides 52, 62 (FIGS. 5 and 6). Theneedle 40 reads the even-numbered pick and the needle 30 the oddnumberedpick. One and the same pick, for example an even pick in this instance,is thus successively read twice by the needle 40, despite the fact thatthe cylinder has moved on. The movement of the guides is so controlledthat the pattern card is read by the needles in accordance with thefollowing table and in the manner illustrated in FIGS. 7-10.

In FIGS. 7-10 the reading points (holes) of the pattern card arenumbered as 1-11.

According to FIG. 7 the second pick is read for the forward motion V,and the first pick is read for the rearward motion R.

According to FIG. 8 the third pick is read for the forward motion V, andthe second pick is read for the rearward motion R.

According to the FIG. 9 the fourth pick is read for the forward motionV, and the third pick is read for the rearward motion rearward motion R.

According to FIG. 10 the fifth pick is read for the forward motion U,and the fourth pick is read for the rearward motion R.

Instead of cams 38, 48 it is possible to use, in a known manner, areciprocating bar. The lifting of the needles 30, 40 and of the slidablelocking members 17, 27 may be controlled from a single camshaft. Insteadof using a compression spring 39, 49 for each two-part lever, it ispossible to use a single spring between the parts 33 and 34.

With the above described dobby machine direct reading and direct controlof the needles is rendered possible. Also, two needles suffice per shaftfor controlling both the forward and backward motion. It is possible toincrease the working speed owing to the direct control exercised. Asonly the position of the holding hooks 35a, 45a, and not theirforce-locking action, is controlled by the reading needles 30, 40, thepattern card is not subjected to excessive loading.

What we claim is:

1. In a dobby machine having a dobby shaft and means for feeding aperforated pattern, the combination of a reciprocable retaining hook,linkage means connecting said retaining hook with said dobby shaft, atwo-part actuating lever comprising first and second lever parts pivotalabout a common pivot and movable relative to one another, said secondlever part having hook means and constituting a holding hook selectivelyengageable with and disengageable from said retaining hook, said fistlever part having sensing means for sensing a pattern fed by said feedmeans and means engageable with said second lever part to move saidholding hook in position to engage said retaining hook and meansengageable with said second lever part to lock said holding hookstationary in engagement with said retaining hook.

2. A combination according to claim Lin which said second lever part ispivoted at one end and has said holding hook at the opposite-end, and inwhich said locking means comprises a movable locking member engageablewith said second lever disengage said second lever part from saidlocking member.

4. A combination according to claim 1, in which said locking means isengageable with said second lever part to hold said holding hook out ofengagement with said retaining hook.

5. A combination according to claim 1, in which said first lever part ispivoted at one end and in which said sensing means comprises a patternreading needle engageable with said pattern and connected directly withthe other end of said first lever part.

6. In a dobby machine having a frame, a dobby shaft and means forfeeding a pattern, the combination of a reciprocable retaining hook,linkage means connecting said retaining hook with said dobby shaft, aholding hook pivotally movable about a pivot on said frame between anengaged position in which said holding hook is in engagement with saidretaining hook and'a disengaged position in which said holding hook isout of engagement with said retaining hook, means for reading a patternfed by said feeding means, means connecting said pattern reading meanswith said holding hook to move said holding hook between said disengagedposition and said engaged position in accordance with said pattern, andmeans for locking said holding hook in engaged position, said holdinghook being movable longitudinally relative to its .pivot to disengagesaid holding hook from said locking means. v

7. A combination according to claim 6, in which said pivot comprises apivot pin and in which said holding hook has an elongated openingreceiving said pivot pin to provide for both pivoted and translatorymovement of said holding hook relative to said pivot pin.. i

8. In a dobby machine having a frame, a dobby shaft, a rocker memberconnected with said dobby shaft and means for feeding a pattern, thecombination of a reciprocable retaining hook, means on said frame forguiding said retaining hook in a rectilinear path of reciprocation,linkage means connecting said retaining hook with said rocker member, aholding hook pivotally mounted on said frame for pivotal movementbetween an engaged position in which said holding hook is in engagementwith said retaining hook and a disengaged position in which said holdinghook is out of engagement with said retaining hook, means for reading apattern fed by said feeding means, means connecting said pattern readingmeans with said holding hook to move said holding hook between saiddisengaged position and said engaged position in accordance with saidpattern and means for releasably locking said holding hook stationaryrelative to said frame in said engaged position.

9. A combination according to claim 8, in which said holding means ismovable longitudinally relative to its pivot by said retaining hook todisengage said holding hook from said locking means.

10. A combination according to claim 8, in which said I means connectingsaid pattern reading means with said holding hook comprises avleverpivoted on said frame coaxially with said holding hook and havingabutment means engageable with said holding hook to move it between saiddisengaged and engaged positions.

1. In a dobby machine having a dobby shaft and means for feeding aperforated pattern, the combination of a reciprocable retaining hook,linkage means connecting said retaining hook with said dobby shaft, atwo-part actuating lever comprising first and second lever parts pivotalabout a common pivot and movable relative to one another, said secondlever part having hook means and constituting a holding hook selectivelyengageable with and disengageable from said retaining hook, said fistlever part having sensing means for sensing a pattern fed by said feedmeans and means engageable with said second lever part to move saidholding hook in position to engage said retaining hook and meansengageable with said second lever part to lock said holding hookstationary in engagement with said retaining hook.
 2. A combinationaccording to claim 1, in which said second lever part is pivoted at oneend and has said holding hook at the opposite end, and in which saidlocking means comprises a movable locking member engageable with saidsecond lever part at the holding hook end thereof.
 3. A combinationaccording to claim 2, in which said second lever part is longitudinallymovable relative to said pivot to disengage said second lever part fromsaid locking member.
 4. A combination according to claim 1, in whichsaid locking means is engageable with said second lever part to holdsaid holding hook out of engagement with said retaining hook.
 5. Acombination according to claim 1, in which said first lever part ispivoted at one end and in which said sensing means comprises a patternreading needle engageable with said pattern and connected directly withthe other end of said first lever part.
 6. In a dobby machine having aframe, a dobby shaft and means for feeding a pattern, the combination ofa reciprocable retaining hook, linkage means connecting said retaininghook with said dobby shaft, a holding hook pivotally movable about apivot on said frame between an engaged position in which said holdinghook is in engagement with said retaining hook and a disengaged positionin which said holding hook is out of engagement with said retaininghook, means for reading a pattern fed by said feeding means, meansconnecting said pattern reading means with said holding hook to movesaid holding hook between said disengaged position and said engagedposition in accordance with said pattern, and means for locking saidholding hook in engaged position, said holding hook being movablelongitudinally relative to its pivot to disengage said holding hook fromsaid locking means.
 7. A combination according to claim 6, in which saidpivot comprises a pivot pin and in which said holding hook has anelongated opening receiving said pivot pin to provide for both pivotedand translatory movement of said holding hook relative to said pivotpin.
 8. In a dobby machine having a frame, a dobby shaft, a rockermember connected with said dobby shaft and means for feeding a pattern,the combination of a reciprocable retaining hook, means on said framefor guiding said retaining hook in a rectilinear path of reciprocation,linkage means connecting said retaining hook with said rocker member, aholding hook pivotally mounted on said frame for pivotal movementbetween an engaged position in which said holding hook is in engagementwith said retaining hook and a disengaged position in which said holdinghook is out of engagement with said retaining hook, means for reading apattern fed by said feeding means, means connecting said pattern readingmeans with said holding hook to move said holding hook between saiddisengaged position and said engaged position in accordance with saidpattern and means for releasably locking said holding hook stationaryrelative to said frame in said engaged position.
 9. A combinationaccording to claim 8, in which said holding means is movablelongitudinally relative to its pivot by said retaining hook to disengagesaid holding hook from said locking means.
 10. A combination accordingto claim 8, in which said means connecting said pattern reading meanswith said holding hook comprises a lever pivoted on said frame coaxiallywith said holding hook and having abutment means engageable with saidholding hook to move it between said disengaged and engaged positions.